The use of pet doors for permitting an animal to enter and exit a residence is known. Such known pet doors are commonly installed in an exterior door and are manufactured to accommodate animals of a variety of sizes. Typically, such pet doors are permanently installed in the exterior door by removing a section of the exterior door and installing the pet door in its place. Such installations therefore require irreparably altering the exterior door. However, this may not be desirable as exterior doors can be very costly, as they are typically constructed of solid wood or steel. Moreover, a pet door may only be needed for the limited period of time that the pet owner lives at the residence where the pet door is installed (e.g. in a rental property). Also, a pet owner may desire to remove the pet door on a temporary basis for security reasons.
Certain pet doors are known which do not require permanent installation. For example, U.S. Pat. No. 6,164,013 discloses a pet door which may be installed in the opening between a door frame and an ajar door. However, such a pet door prevents use of the house door to which it is installed and is not suitable for use with an exterior door, which preferably remains closed when not in use for security reasons.
Therefore, pet doors not requiring permanent installation are needed. One attempt at providing for this need involves the use of pet portals in a window. Such portals afford the advantage of not requiring permanent installation and do not interfere with operation of a door. However, known pet portals for installation in a window do not blend well with the window into which they are installed and have other disadvantages. For example, U.S. Pat. No. 6,253,711 discloses a pet portal which may be installed in a window, but requires the pet to maneuver through a complicated U-shaped interior passageway in order to reach the exit. Such a portal may not be suitable for certain pets due to size and other physical limitations. Moreover, such a device does not fit entirely within the window frame but rather protrudes from the window, resulting in a awkward structure which may fall out of the window and may also present a hazard to those walking by. Such a device is also unsightly, relatively complicated to manufacture, is difficult to package, requires considerable inventory storage space, i.e. because of its box-like configuration), and does not blend well with windows or building structures.
Moreover, pet cages and litter boxes that may be installed in a window are also known, but do not permit ingress and egress of a pet from the building in which they were installed. Examples are set forth in U.S. Pat. Nos. 5,469,807; 5,522,344; and 5,842,438. These devices serve a specific, unrelated purpose and are also large, unsightly and do not blend well with the aesthetics of the windows into which they are installed.
Therefore, there exists a need in the art for a low profile pet door which does not require permanent installation and which permits a pet to enter and exit a structure at will. There further exists a need for such a pet door which blends well cosmetically with windows and building structures, is easy to install and uninstall, and which is easy to manufacture, store, package, and transport.